Process of and means for cementitious molding



May 8, 1928.

N. C. JOHNSON PROCESS OF AND MEANS FOR C EMENTITIOUS MOLDING Original Filed June 17, 1925 Patented May 8, 1928.

UNITED STATES NATHAN C. JOHNSON, OF ENGLEWOOD, NEW JEBSEYH PROCESS AND MEANS FOR CEMENTITIOUS MOLDING. Original application lled June 17, 1925, Serial No. 37,625. Divided this 1,668,723 PATENT OFFICE.

application filed February 14,

1927. Serial No. 168,185.

This invent-ion relates to products for surfacing and molding cementitious materials suchas concrete and to processes for mak-' ing and utilizing such products.

'The use of concrete has been greatly. restricted by reason of unsightly form marks and other surface characteristics which in the past could only be removed'or obscured by expensive or undesirable methods. Heretofore, in attempts toremove the undesirable surface, marks, strong mineral acids or other chemicals have been used for scrubbing down set or hardened concrete, and in other ways forgiving a desirable appearance by exposing the aggregate and eating away the cement'surface, but this is in some caSes impractical. Costly and inefficient mechanical methods have had a limited use.

With 10 marks and other undesirable surface characteristics may be obliterated and a rough textured'concrete surface with the aggregate exposed to any desired extent may be provided in a reliable, cheap, and easy manner, but without affecting or endangering the strength of the concrete body. This is very desirable for many purposes, such for example as to give a pebbleor rock-like surface-t0 concrete, or

g 80 to permit a better bonding of plaster or cement to a concrete surface; or to bond together in a manner two portions of a concrete structure, such as a wall, that are oured at different times, since with this surfiicing treatment, the second pouring will unite and bond itself perfectly to the rough and clean surface of the first portion to set.

Also, according to this invention, the outgenerally over rich in cement may be removed with the resulting elimination of the harmful cracks which often occur in this rich cement surface due to the fact that it has a different coefficient of expansion from that of the main body of the concrete.

According to the presentinvention I provide a suitable concrete set-inhibiting reagent or medication .substance or substances which will render the cement at the surface layers unsound, thus preventing or very reatly delaying the setting of the surface layer of the concrete. Accordin to one form of the invention this medication substance may be applied to a suitable carthe present invention the form.

- yond the pleasing rough finishheretofore impossible through a body of er surface layers of the concrete which are rier or backing such as a web of paper or fabric, either felted or woven, or other ficoncrete forms or otherwise placed with the medication the concrete. medication more or less exposed to Furthermore, if desired the substance may be embodied in "a suitable colloidal composition or vehicle such that a predetermined limited quantity of the medication substance is gradually and uniformly delivered up to the concrete by dialysis.

on concrete is pouredinto the forms ings of the type agent leaves vehicle andis slowly diffused into the con crete, thus affectin the surface layers of the cement to the esired or predetermined depth in a manner to change the composition of the cement by balancing the same, thereby rendering it unsound but without the, reagent afi'ectin the cement lying beredetermined desired depth that was inten ed-to be affected. After the forms and the carrier are removed, the affected cement layers may be easily brushed or above indicated, the rewashed awayleaving the rough textured surface.

v The invention comprises the novel prod net as above referred to and-also the process of manufacturing and applying such .product to the treatment of a concrete body.

- In the drawings, Fig. 1 is a sectional view concrete and the accompanying forms therefor,'showing one manner'of using my invention in practice; and

Fig. 2 is a view illustrating the application of the set-inhibiting composition to a carrier of sheet material.

Referring to'Fig. 1, suitable forms of well known construction are indicated at 5.

I pon these forms a carrier or backing of sheet material 6 is provided and has its surface, which is adapted to contact with the concrete, treated with a set-inhibiting composition as indicated at- 7. The sheet material or backing may be secured to the forms by'an adhesive or by the use of nails or tacks, as indicated at 8, or both. The

concrete body indicated at 9 may be of any of the. well known compositions and is poured into the forms in the "usual manner.

The main body of'the concrete will be-' EISSUED the carrier and/or the colloidal i come set in the usual manner, but, atithe *surfaces of the concrete which contact with rain washing and weathering.

the set-inhibiting material 7, the setting action will be prevented or Accordingly, after the main body of the concrete becomes set, the forms 5, together with the sheet material 6, may be removed before the surface layers of the concrete are hardened. These surface layers may then be removed by brushing or washingdown or may be removed merely by the action of The medicationv substance acts to prevent the normal setting action of the cement between and around the particles of aggregate but only to a limited and controlled depth, thereby making evident a fine etched appearance and conferring a pleasing texture and relief. I

Many different and widely varying substances may be used as a set-inhibiting-rcagent or medication; for example, they may consist either of mixtures of sugar products, .of metallic salts or of glucocides or glucose, molasses, dextrines either with or without metallic salts, or metallic salts either with or without other substances. Such reagents or compositions thereof may be applied in thin layers directly upon the flexible backing of sheet material or preferably they may be embodied in suitable colloidal vehicles to form compositions, one example of which will now be described.

A mixture of orange shellac. gum and manilagum dissolved in suitable quantities of alcohol and with or without waxes is prepared with the desired consistency to forms. tenacious adhesive colloidal vehicle. For this purpose about 2 pounds of the shellac and about 2 pounds of the manila gum may be dissolved in about 3 quarts of alcohol. "To this colloidal vehicle a. suitable reagent or reagents or medication is added which will have the property of inhibiting. the normal setting action of a con crete mixture to a limited depth when a plied to the surface thereof. Among tie reagents or medication substances which maybeused in this connection are aluminum chloride, magnesium saccharate and magnesium chloride in suitable proportions, such for example as aluminum chloride FA oz., magnesium saccharate 6% oz., magnesium chloride 2 oz., these metallic salts being mixed with a small quantity of water, 'say one-half pint. A composition made according to this formula and with these amounts will produce about one gallon of the colloidal substance.

Greater quantities of the reagents or medication will affect greater depths from the concrete surface by reacting with greater quantities of the cement if such action is desired.

While various compositions or emulsions of water-distensible colloids may be used, it

greatly delayed.

without the isdesirable in commercial work that the medication be carried in a vehicle which is insoluble and/or not .distensible except in the alkaline waters such as are produced in concrete and pervade the concrete during the reaction between .the water and Portland cement. Another example of such a water insoluble body or vehicle is casein, either with or without formaldehyde.

The set-inhibiting material either with or colloidal vehicle maybe brushed, ri'nted on, or otherwise spread upon the acking of sheet material and is preferably allowed to substantially dry out to form a toughened flexible thin layer; or in some instances it may be found desirable to saturate the backing'with there.- agent.

As a web of backing material, paper or inexpensive cloth may be used or in some instances it may be found desirable to use 'a backing of sheet metal, expanded metal thermore, the set-inhibiting material may be applied to the backing so as to produce figured or pattern eiiccts as well as to remove the entire surface layer. In the example shown in Fig. 2 a web of material 10 has areas as at 11. treated with the setinhibiting material and alternate areas 12, which are untreated, thus simulatin a brickwork design. By using such a pro uct' a representation of the design will be inscribed upon the surface of the concrete body, the untreated surface areas being revealed in relief.

Although in the drawings the product is illustrated as used upon a vertical wall, it will be understood that the same or similar products may be used in other types of construction, such as for instance, ceiling constructions where a finished surface is desired. It may also be used in top surface construction, such as on sidewalks, floors, porch floors and the like. Also, where it is desired to securely bond one section of a concrete structure to another section which is to be poured later, a rough surface for bonding purposes may be formed in accord ance with this invention by treating the sursurt'ac'e to expose. clean aggregate particles which will allix themselves within the concrete body later poured thereon and make possible a durable bonding action.

This application comprises a division of the invention disclosed in my copending application, Serial No. 37,62 filed June 17, 1925, for Method of and composition for treating concrete, which in turn is a continuation in art of my application, Serial No. 690,215, fi ed Feb. 2, 1924 for Improvements in concrete and method of and substance for producing sam lit While I have described my invention in considerable detail and with respect to preferred forms of the product embodying the invention, and the preferred methods or processes for making and using the same, it will be understood by those skilled in the art, after having understood my invention, that various changes and "modifications may be made without departing from the spirit and scope; of the invention, and pended claims to cover all suchmodificatio'ns and changes as come within the spirit of the invention.

\Vhat I claim as new and desire to secure' by Letters Patent is:

1. The combination of a mold for cementitious material, a carrier located adjacent to a molding surface of said mold and a cement destroying composition carried by said carrier on that surface which is adapted for contact with the cementitious material when the mold is filled.

2. The combination of a mold for cemen titious material, a fibre backing located in surface engagement with a molding surface of said moldand a cement destroying composition carried by said backing on that surface which is'adapted for contact with the cemcntitious material when the mold is filled. i

3. The combination of a mold for. casting cementitious material into the form of a wall, a paper carrier located in surface engagement with an inner surface of said mold and a cement destroying composition carried by said paper in a manner to .contact with said-cementitious material at one surface of the wall formed thereby.

4. Means adapted for use in molds for molding cementitious material comprising a carrier of pliable material and a cement destroying composition carried by said carrier on that surface which is adapted for contact with the ccme'ntitious material when the mold is filled. 5. Means adapted for use in molds for molding cementitious material comprisinga roll of building paper and a cement destroying composition carried by said paper on that'surface which is adapted for contact with the cementitiou's "material when the mold is filled.

6. Means adapted for use in molds for molding cementitious material comprising a carrier of pliable material and-a cement destroying composition in the form of a predetermined design carried by said carrier on that surface which is adapted for contact with the cementitious material when the mold is filled. 7. The combination of a mold for casting cementitious material, a fibre carrier positioned contiguous to the inner surface of said mold, said carrier having a cement destroying composition on the surface thereof I aim in the apadapted to make contact with said cementitious material and means for temporarily sccuring said carrier to said mold to position it during the mold-filling operation and to permit of its removal been 0 )ened.

8. eans for acting upon concrete surfaces during the setting thereof to eliminate from the concrete body the surface layer, which comprises a carrier of fibrous material bearing a thin layer of a colloidal vehicle in which is incorporated a cement destroying composition.

9. In combination a sheet of flexible material bearing-a thin layer of a composition for treating concrete surfaces to eliminate the surface layer of the concrete, which composition comprises a reagent material which will prevent the setting of the cement of the concrete with which it contacts or substantially delay the setting of the same-beyond the period in which other portions of said cement out of contact with said reagent will set.

10. 111 combination a sheet of flexible material bearing a thin layer of a composition for treating concrete surfaces to eliminate the surface layer of the concrete, which composition comprises a reagent material which will prevent the setting of the cement of the concrete with which it contacts or substantially delay the setting of the same beyond the period in which other portions of said cement out of contact with said reagent will set, and also comprising a colloidal vehicle. inwhich the reagent material is incorporated.

11. In combination a sheet of flexible material bearing a thin layer of a composition for treating concrete surfaces to eliminate the surface layer of the concrete, which composition comprises a colloidal vehicle in. which is incorporated a reagent material capable of reacting upon the cement of the concrete to unbalance the composition of' the same and render it unsound or nousetting, the" said colloidal composition having the property of being insoluble in plain or ordinary Water, but distensible or soluble in alkaline waters extruded from wet concrete.

12. A product as described in claim 11, characterized by the facttliat the colloidal vehicle comprises a gumsubstance.

13. A product as described in claim 11, characterized by the fact that the colloidal vehicle comprises a resinous substance distensible in alkaline waters.

14. .A product for treatingconcrete. surfaces to eliminate the surface layer of the concrete, which comprises a composition containing a reagent material which will prevent the setting of Portland cement, said material being incorporated in a colloidal vehicle comprising gum dissolved in a solvent which enables the reagent to be inafter the mold has Hll corporated with'the colloidal vehicle without precipitation of the gum, said com osition being applied in a thin layer to a exible backing.

15. A product as described in claim'l i, characterized thereby 'that'the colloidal vehicle comprises dissolved orange shellac and, manila gum.

16. A product for treating concrete surfaces to eliminate the surface layer of the cement thereoflwhich comprises a backing of paper or the like bearing a thin layer of a composition containing a reagent material which will prevent the setting of the cement with which it comes into contact or substan: tially delay the setting of the -'same beyond the periodin which other portions of the cement out of contact with said-reagent will set, said composition being substantially free of any mineral-acid.

17. As anarticle of manufacture-a web of material to be used as a linin for con crete forms, having a concrete set-inhibiting material applied thereto. I

18. As an article of manufacture, a Web of material to be used as a lining for -con'- crete forms, having applied to a surface thereof anon-volatile vehicle containing a concrete set-inhibiting substance.

19. As an article of manufacture, a lining for concrete forms, having on a surface thereof a dried vehicle containing a concrete setinhibiting substance. 7

20. Process of-forming concrete structures which consists in applying to the concreteforms a web of lining material bearing a concrete set-inhibiting composition on the surface thereof whiclris adapted for contact with the concrete, pouring the concrete mixture into the forms against said set-inhibting composition, allowing the concrete to at least partially set, then removing the forms and lining material and the surface layers of the concrete which have been acted upon by said set-inhibiting composition.

21. Process of forming concrete structures with designs inscribed thereon, which consists in applying to the concrete forms a; web of lining material bearing a concrete set-inhibiting composition on certain surface areas thereof following in'outline the desired design, pouring the concrete mixture into the forms against said lining material and composition, allowing the concrete to at least partially set, then removing the forms and lining material, and finally removing from the body of concrete the surface layers of the areas which have been acted upon by said set-inhibiting composition to reveal the remaining areas in relief.

the forms against saidcomposition, allowingthe-concrete to at least partially set, then removing the forms, and finally removing from the body of concrete the surface lawers of the areas which have been acted upon 'by said set-inhibiting composition to reveal the remaining areas in relief.

23. Process of forming concrete structures which iconsists in applying to the concrete forms a web of lining material bearing a nonvolitile vehicle incorporating a concrete setinhibiting composition on the wehisurface which is adapted for contact with the con crete pouring the concrete. mixture into the forms against said: set-inhibiting composition,--allowing the concrete to at least partially setgthen removing the forms and linking materialand the surfacelayers of the concrete. which have beenacted upon by said set-inhibiting composition.

24. Process of formingconcrete structures which consists: in applying to .the concrete forms a web of lining material bearing a dried vehicle incorporating a concrete setinhibiting; composition on the web surface which is adapted for contact with the concrete, pouring the concrete mixture into the forms against said set-inhibiting composition, allowing the concrete to at least partially set, then removing the forms". and lining materialand the surface layers which have been acted upon byjsaid set-inhibiting composition.

25. Process of forming concrete structures which consists in applying to the concrete forms a web of lining material bearing a dried vehicle incorporating a concrete setinhibit-ing composition on the web surface which is adapted for contact" with the concrete, the vehicle being one insoluble in water other than alkaline water, pouring the concrete mixture into the forms against said set-inhibiting composition, allowing the concrete to at least partially set while the vehicle becomes distended by the alkaline waters extruded from the wet concrete, then removing the forms and lining material and the surface layers which have been'acted upon by said set-inhibiting composition.

In testimony whereof I have signed my name to this specification.

NATHAN c; JOHNSON. 

